As shown in FIG. 1, a yoke 90 used in an automobile steering system, the steering which comprising a rod portion 91 and a fork portion 92. According to existing manufacturing technique, the edge of tip 923 of the fork portion 92 is to be cut into arc shape, and the two pairs of diagonal edges of the inner side of the fork portion 92 are to be cut into chamfer (can also be called trimming), FIG. 2 shows the shape of the one pair of the diagonal edges 921 and edge 922 after being cut. Current manufacturing process uses blanking press machine for cutting the tip of fork portion and the two pair of diagonal edges of yoke 90.